Sofa



FIG. 1 is a front perspective view of a sofa showing our design;

FIG. 2 is a side and front perspective view;

FIG. 3 is a side and rear perspective view; and

FIG. 4 is a top plan view thereof.

The side of the sofa not shown is like the side shown. 

The ornamental design for a sofa, as shown and described. 